Add support for SQL EXISTS and exists-based JOIN about cqengine HOT 4 CLOSED

Changes committed to trunk:

QueryFactory.existsIn(IndexedCollection<F> foreignCollection, Attribute<O, A> 
localKeyAttribute, Attribute<F, A> foreignKeyAttribute)
and
QueryFactory.existsIn(IndexedCollection<F> foreignCollection, Attribute<O, A> 
localKeyAttribute, Attribute<F, A> foreignKeyAttribute, Query<F> 
foreignRestrictions)

Example usage: 
http://cqengine.googlecode.com/svn/cqengine/trunk/src/test/java/com/googlecode/c
qengine/examples/join/SqlExists.java

Also, using this support for JOINs between indexed collections: 
http://cqengine.googlecode.com/svn/cqengine/trunk/src/test/java/com/googlecode/c
qengine/examples/join/SqlExistsBasedJoin.java

Original comment by [email protected] on 27 Jan 2013 at 10:11

• Changed title: Add support for SQL EXISTS and exists-based JOIN
• Added labels: Type-Enhancement
• Removed labels: Type-Defect

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Original comment by [email protected] on 27 Jan 2013 at 10:12

• Changed state: Done

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Hi Niall, I've been looking at using cqengine for a project and came across this functionality you added. When I try to use the SQL WHERE EXISTS statement as in the example above with the SQLParser, I keep getting parser failure:
Request was not successful: Failed to parse query at line 1:30: extraneous input 'EXISTS' expecting {'(', K_NOT, IDENTIFIER, STRING_LITERAL}

Browsing through the examples in your test, I'm guessing this functionality has only been added to the CQN dialects, but not currently supported in SQL parser?

Thanks,
Ann

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See Niall's reply at https://groups.google.com/forum/#!topic/cqengine-discuss/V-GsNSPIHAA.

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